Contradiction with Matthew 10:5-6
These verses describe Jesus sending the disciples only to the "lost sheep of the house of Israel," which could be seen as a contrast to the idea of including Gentiles as in Acts 15:13.
Matthew 10:5-6: These twelve Jesus sent forth, and commanded them, saying, Go not into the way of the Gentiles, and into [any] city of the Samaritans enter ye not:
Contradiction with Matthew 15:24
Jesus states he was sent only to the "lost sheep of the house of Israel," which might appear contradictory to the acceptance of Gentiles signified in Acts 15:13.
Matthew 15:24: But he answered and said, I am not sent but unto the lost sheep of the house of Israel.
Contradiction with Acts 10:14
Peter initially resists the idea of accepting Gentiles by saying he has never eaten anything unclean, which clashes with the acceptance of Gentiles emphasized in Acts 15:13.
Acts 10:14: But Peter said, Not so, Lord; for I have never eaten any thing that is common or unclean.
Contradiction with Galatians 2:11-12
Paul confronts Peter for withdrawing from Gentiles, showcasing tension regarding Gentile inclusion, potentially conflicting with the consensus seen in Acts 15:13.
Galatians 2:11-12: But when Peter was come to Antioch, I withstood him to the face, because he was to be blamed.
Contradiction with Romans 11:1
Paul begins explaining that God has not rejected Israel, which can seem contrary to the inclusive direction (Gentiles) of Acts 15:13.
Romans 11:1: I say then, Hath God cast away his people? God forbid. For I also am an Israelite, of the seed of Abraham, [of] the tribe of Benjamin.